UHPLC-Q-Exactive Orbitrap MS/MS based untargeted lipidomics reveals fatty acids and lipids profiles in different parts of capelin (Mallotus villosus)

The capelin (Mallotus villosus) is a significant fish species with high nutritional value. This study comprehensively investigated the fingerprinting of the lipidome of its head, meat, roe, and viscera, based on an untargeted lipidomic strategy. Results showed that unsaturated fatty acids accounted for more than 55 % of the total fatty acids in the capelin, especially docosahexaenoic acid (DHA, 7.65 −19.83 % of total fatty acids) and eicosapentaenoic acid (EPA, 7.79 −16.91 %). Additionally, 1206 lipid molecules involving 30 major classes were detected. Among these molecules, phosphatidylcholine (PC) (12:1/26:1), PC (5:0/22:5), PC (13:0/24:4), PC (16:0/16:0), PC (19:0/20:3), and phosphatidylethanolamine (PE) (39:0/15:1) were the characteristic lipids in roe, then ceramides (Cer) (t19:1/24:4), Cer (t20:0/18:2), Cer (t22:1/18:2), Cer (t19:1/18:2), Cer (t16:1/26:1), and Cer (d16:0/24:4) were the characteristic lipid in viscera. Overall, this study provided the first interpretation of the lipidome of capelin, which could serve as a reference for future studies on nutritional value, ecology, and traceability of geographic origin.